( Reaffirmed 2003 ) Indian Standard SPECIFICATION FOR GLASS TUBES FOR MEDICAL THERMOMETERS Laboratory Glassware and Related Apparatus Sectional Committee, CDC 33 Representing Borosil Glass Works Ltd, Bombay Chaiiman DE S. R. LELE Members National Test House, Calcutta Srrar K. L. BANEIUEE Hemine Institute, Bombay DB N. K. DUTTA Sasx Y. S. NIMBKA~ ( AIlernufe ) Centrsl Scientific Instruments Organization DEP. S. GILL ( CSIR ), C$andigarh DE R. N. MATHUB ( Alternate 1 +he Gang& Glass Works Private`Ltd, Belawali SHBI HABI DATTA Directorate General of Technical Development, SHBI S. R. KHANNA New Delhi Central -Glass and Ceramic Research Institute Da S. KKJXAB ( CSIR ), Calcutta The Scientific Indian Glass Co Ltd, Calcutta Da S. C. -NIYOOY National Physical Laboratory ( CSIR ), New SHBI PBEM PEAKASH Delhi Ministry of Defence ( R & D ) SHBI K. V. RA~ACHAND~AN Indian Institute of Technology, New Delhi PROF V. RAMAKEI~ENA Glaxo Laboratories ( India ) Private Ltd, SHEI N. RANQASWAMY Bombay National Instruments Ltd, Calcutta SERI D. C. ROY SBBI A. SANEARANABAYAKAN Toshniwal Brothers Private Ltd, Bombay SHRI D. J. RAO ( AZternate) National Chemical Laboratory ( CSIR ), Poone DE D. N. SE% Development Commissioner, Small Scale IndusDR H. A. SHAH tries, New Delhi Indian Council of Medical Research, New DE P. G. TULPULE Delhi Seraikella Glass Works Private Ltd, Kandra Saar P. C. VARSH~`EI Saar P. P. CXAXDBA ( Alternate ) DR SADQOPAL, Director General, IS1 ( Ex-oficio Member ) Deputy Director General SHBI G. P. SARASWAT Assistant Director ( Chem ), IS1 ( Secretary Continued on page 2 ) INDIAN MANAK STANDARDS BHAVAN, 9 BAHADUR NEW DELHI INSTITUTION SHAH 110002 ZAFAR MARG x5:4529-1968 ( continuedfiom page 1 ) Thermometers Convener Sam T. D. BANSAL SBBI H. K. BANEBJEE Subcommittee, Nation81 Phggicsl Delhi CDC 33 : 2 Laboratory ( CSIR ). Representing Now Members Nation81 Imtruments Ltd. C8lCUtt8 SHBI J. SANYAL ( Alternate SHBI K. L. BAXZBJZZ Saz~ A. N. DIXXT SEBI K. GANOAYYA SEBI HABI DATTA SHBI D. R. KOTEABI SHBI V. KBISENAMOO~THY ) SEES R. K. KOTEARI ( Alternate ) Directorate General of Technical Development. New Delhi KUMAXI A. MINI India Meteorological Department, New Delhi SHRI S. GOPINATH ( Alternate ) MAJ V. P. SETHI Directorate General Armed Forces Medical Services ( Ministry of Defence ) SBBI Y. D. SHARMA Dutta Scientific Works, Solsn Nation81 Test House, C8lCUtt8 Ministry of Defence ( R & D ) Directorate General of Hwith Services, New Delhi The Gang8 Glass Works Private Ltd, B818w8li Jintan Clinical Thermometers Co ( India ) Private Ltd, Surendrsnagsr Panel for Thermometer Convener Sam HA~I DATTA Tubes, CDC 33 : 2 : 1 The Gang8 Glass Works Private Ltd. Balawali Hicks Thermometers ( India ) Ltd, Mussoorie Jintan Clinical Thermometers Co ( Indis ) PI'iVSte Members SHBI VED PRAKA~H GUPTA SEBI D. R. KOTHABI SHEI Y. D. SEABMA Ltd. Surendranagar Dutta Scientific Works. Solan IS:45W-l968 Indian Standard SPECIFICATION FOR GLASS TUBES FOR MEDICAL THERMOMl$ERS 0. F 0 R'E W 0 R D 0.1 This Indian Standard was adopted by the Indian Standards Institution on 29 January 1968, after the draft finalized by the Laboratory Glassware and Related Apparatus Sectional Committee had been approved by the Chemical Division Council. 0.2 Medical thermometers are being manufactured in the country on a large scale. ` Indian Standard specification for clinical thermometers ' ( IS : 3055-1965 ) has already been published and specifications for other medical thermometers are under preparation.. Since glass tubes, the basic raw material for the manufacture of such thermometers, have to be of a specific type, the Laboratory Glassware and Related Apparatus Sectional Committee decided t6 prepare this standard. 0.3 The object of this standard is to enable manufacturers of ,medical thermometers to select glass tubes of the right type for producing quality thermometers. 0.3.1 A separate standard is being prepared general purpose and reference thermometers. 0.4 This standard has clause 5.5.1 which between the purchaser and the supplier. for glass tubes for for agreement provides 0.5 For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS : 2-1960'. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard. 1. SCOPE 1.1 This standard prescribes the requirements and the methods of sampling and test for glass tubes used in the manufacture of glass type medical thermometers, including veterinary thermometers. *Rules for rounding off numeric1 velues ( revised ). 3 2. TERMINOLOGY 2.1 For the purpose of this standard the definitions given in IS : 13821961* and IS : 2627-1963t, in addition to the following capillary tubes and bulb tubes. shall apply. 2.2 Glass Tabes - 3. SHAPE 3.1 Tbe shape, that is, the cross-section of the capillary prismatic having a lens' front as shown in Fig. 1. tubes shall be FXG. 1 CROSS-SECTION OF CAPILLARY TUBES OF MEDICAL TI-IERMOMBTERS 3.2 The bulb tubes shall be :of circular cross+ection. 4. MATERIAL 4.1 Appearance -Glass capillary and bulb tubes shall be of clear, transparent glass free from occlusions, striae, stresses and other visual defects such as bubbles, double bore, knots, reflection failures and roughness of the bore. 4.1.1 The capillary tubes shall be provided with a white or yellow back. NOTE - Additional coloured glese strip OF&rips may be provided suitably on the capillary tubes. 4.2 The capillary tubes shall not have ( a ) any double bore at the two ends as viewed through a microscope having minimum magnification of 250 times, and ( b) any angular twist as measured by change in the apparent wrdth of the bore as seen by a plastic scale. 4.3 The lens front of the capillary tubes shall magnify the mercury column in the bore to a,width of at least one millimetre ( see 4.3.2.1 of IS : 3055~1965$). l Olos~ary of terms relating to glass industry. taloss8V of terms relating to liquid-in-glesa thermometerr. SSpeciscation for clinical thermometers. IS. : 4529 - 196% 4.4 The bulb tubes shall not have any stone or air line visible to-the naked eye. 5. REQUIREMENTS 5.1 The tubes shall not devitrify during two heatings for three minutes at a stretch in an oxidizing flame of a burner. `5.2 Coefiicient of Linear Thermal Expansion - The average coefficient oflinear thermal expansion of the tubes shall be &5 f 0.3 x 10-B perdeg in the range of 0" to 100°C. 5.2.1 The difference in the coefficients of linear thermal expansion of the capillary tubes and the bulb tubes shall not be more than 0.2 x lad per deg. 5.2.2 The coefficient of linear thermal expansion of opal glass, used for providing backing and coloured strips, shall be such that it does not shatter when the capillary tubes are heated repeatedly as given in 5.1. 5.3 Stability of Bulb Tubes - The bulb tub&s shall' be considered stable if a special thermometer, having a range 0" to lOO"C, made with that bulb tubing without a maximum indicating device, complies with the following requirements: a) The zero shall not rise more than 0.02 deg in the first six months of the manufacture of the thermometer,. and b) After ageing, the zero depression after heating the thermometer at 100°C for one hour, shall not exceed O-05 deg. 5.4 Limit of Alkalinity cribed in IS : 2303-1963*, glass. 5.5 Dimensions 5.5.1 Length - The length of glass tubes between the purchaser and the supplier. shall be as agreed to When graded according to the method presglass tubes shall conform, to Type 5 of the diameter of the capillary tubes shall be not less 5.5.2 Diameter -The than 4 mm and not more than 6 mm when measured with a ring gauge or a shadow graph. 5.5.2.1 The outside diameter of the bulb tubes shall be between `2 and 3.5 mm for use in oral, and 3 and 5 mm for use in rectal, stubby or veterinary, thermometers when measured with a ring gauge or a ,shadow graph. *N&hod of grading glass for alkalinity. 15:4529-l%& 5.53 Bore 5.5.3.1 The shape of the bore of the capillary tubes shall be circular or elliptical. If elliptical, the ratio of the major axis to the minor shall be not more than 2.5. 5.5.3.2 The bore area of the capillary tube for use in oral thermometers shall be not less than 09JO 3 mms and not more than 0903 m*, while for use in rectal stubby or veterinary thermometers, it shall be not less than 0.000 4 mm2 and not more than 0004 mm* when measured, at each end, with a high power microscope having a magnification of not less than 250 times or any other suitable instrument. 5.5.3.3 The bore area at any end shall not differ from the average of the two bore areas by more than 5 percent. 5.5.3.4 The shape of the bore of the bulb tubes shall be circular. 6. PACKING AND MARKING free from moisture, dirt and dust. able cardboard boxes. Alternately, both ends. . 6.2 Marking 6.2.1 Each bag shall be marked with the following information: a) Name of the material; b) Manufacturer's name or recognized Lot number ci from records; 6.1 Packing - Glass tubes shall be packed in sealed polyethylene bags The bags shall be packed in suiteach tube shall be flame sealed at trade-mark, of manufacture if any; to be traced to enable the batch 4 f) Year of manufacture; Accelerated and ageing schedule recommended may also be marked by the manufacturer. e) Bore area and its tolerance, 6.2.2 The packages Mark. NoraIndia with the IS1 Certification The use of the IS1 Certification Mark ia governed by the provisions of the Standards Institution ( Certification Marks ) Act and the Rules and Regulations The ISI Mark on products covered by an Indian Standard made thereunder. conveys the assurance that they have been produced to comply with the requirements of that standard under a well-defined system of inspection, testing and quality control which is devised and supervised by IS1 and operated by the producer. IS1 marked productsare also continuously checked by IS1 for conformity to that standard as a further safeguard. Details of conditions under which a licence for the use of the ISI Certification Mark may be granted to manufacturers or processors, may be obtained from the Indian Standards Institution. 6 IS : 4529 i 1968 7. SAMPLING 7.1 Representative samples of the material adjudged as prescribed in Appendix A. shall be drawn and APPENDIX A ( Clause 7.1 ) SAMPLING OF GLASS TUBES FOR MEDICAL THERMOMETERS A-l. SCALE OF SAMPLING A-l.1 Lot -In a single consignment all the capillary tubes with the same type and size of bore ( or all the bulb tubes for the same type of thermometers produced in the same batch of manufacture ) shall constitute a lot. A-l.2 Samples shall be tested from each lot separately for ascertaining conformity of the tubes in the lot to the requirements ( except stability of bulb tubes ) of this specification. A-l.3 The number of sample tubes to be selected for testing shall depend on the size of the lot and shall be in accordance with Table 1 when the lot contains up to 1 000 tubes and in accordance with Table 2 when the lot contains more than 1 000 tubes. TABLE 1 LOT SCALE OF SAM;L$GT~;sLOTS CONTAINING UP TO SIZE (1) SAWLE SIZE (2) 20 80 ACCEPTANCE NUMBEB (3) 0 1 up to 300 301to 1000 A-l.4 Random Selection - The tubes shall be selected at random from the lot. In order to ensure rendomness of selection random number tables shall be used. In case random number tables are not available, the following procedure may be adopted: Starting from any item count them as 1, 2, 3 ,......, etc, up to r and so on in one order. Every rth item thus counted shall be chosen for the sample, where r is the integral part of N/n, N being the total number of items and n the number to be chosen. 7 IS:4529-1968 TABLE 2 SCALE OF SAMPLING FOR LOTS CONTALNING MORE THAN 1000 TUBES ( Clause A-l.3 ) SAXPLING STAQE SAMPLE SIZE CU~~LTLATIVE SAMPLE (4) 20 40 60 80 100 ACCEPTANCE NUMBEB (5) . * 0 0 1 1 2 REJEOTXON NIJMBEB (6) 2 2 2 : 3 3 LOT SIZE (1) Above1000 (2) (3) First 20 Second 20 Third 20 Fourth 20 Fifth 20 Sixth 20 Seventh 20 *&ceptance not permitted at this 120 140 stage. A-2. NUMBER OF TESTS AND CRITERIA FOR CONFORMITY FOR LOTS CONTAINING UP TO 1000 TUBES A-2.1 Sample tubes, as required in co1 2 of Table 1, shall be selected from the lot in two steps. In the first step at least 50 percent of the Then in the second step from bags in the lot shall be taken at random. each selected bag an equal number of tubes shall be taken at random so as to give the total number of tubes in accordance with co1 2 of Table 1. A-2.2 Requirements Other Than Alkalinity - All the sample tubes shall be individually tested for all the requirements except that ofalkalinity. Any tube which fails to satisfy any one or more of these requirements shall be called a defectiva. A-2.2.1 If, the number of defectives in the sample tubes does not exceed the acceptance number specified in co1 3 of Table 1 the lot shall be declared to conform to these requirements and shall be passed on for alkalinity test (see A-2.3 ). A-2.3 Alkalinity Requirement - The lot having been found to conform to all other requirements in A-2.2, shall be tested for alkalinity. For this purpose, from the sample tubes, a number of tubes shall be taken at random so as to yield after crushing an adequate quantity of glass for one alkalinity test. A-2.3.1 If the result of alkalinity requirement, the lot shall be declared of this specification. A-3. NUMBER FOR LOTS test meets the specified alkalinity as conforming to the requirements FOR 1000 CONFORMITY TUBES lot in OF TESTS AND CRITERIA CONTAINING MORE THAN A-3.1 The sample tubes shall be selected stages at the rate of 20 per stage according 8 at random from the to need as in A-3.2. IS : 4529 - 1968 A-3.2 Requirements conformity follows: for these Other Than Alkalinity requirements shall be Testing and judging done stage-by-stage as Twenty sample tubes shall be taken at random from as many bags in the lot as possible. Each of the 20 tubes shall A tube which fails to satisfy any be tested for these requirements. If the one or more of these requirements shall be called defective. number of defectives found in these 20 tubes equals or exceeds the rejection number corresponding to the first stage in Table 2, the lot shall be rejected without further testing, otherwise testing shall proceed to the second stage. First Stage - Second Stage - In the second stage 20 more tubes shall be taken from the lot at random from as many bags as possible and repreEach of these 20 tubes shall senting as many new bags as possible. If the total number of defectives be tested for these requirements. of both the stages equals or exceeds the rejection number corresponding of the second stage in Table 2, the lot shall be rejected without further testing, otherwise testing shall proceed to the third stage. Third Stage - In this stage 20 more tubes shall be taken from the lot at random from as many bags as possible and representing as many new bags as possible.. Each of these 20 tubes shall be tested for these requirements. If the total number of defectives of all the stages so far is equal to or less than the acceptance number corresponding to this stage in Table 2 the lot shall be declared to conform to these requirements; if it is equal to or greater than the rejection number corresponding to this stage in Table 2 the lot shall be rejected; if it is in. between the corresponding acceptance number and the rejection number the testing shall proceed to the next stage. Fourth and Subsequent Stages - The procedure for the fourth and the subsequent stages, if needed, shall be the same as for the third stage till a decision to reject or to accept the lot for these requirements is reached. lot having been found to conform A-3.3 Alkalinity Requirement -The to all other requirements in A-3.2, shall be tested for alkalinity. For this purpose two alkalinity determinations shall be made; one from the sample tubes of the first stage and the other from the sample tubes of the second stage. The tubes for alkalinity test shall be taken at random from the stage sample so as to yield after crushing an adequate quantity of glass for one test. A-3.3.1 If the two test results for alkalinity specified alkalinity requirement, the lot shall be ing to the requirements of this specification. separately meet the declared as conform- 9